Question

我有我的REST服务：http://localhost:4242/myrestservice/getobject 它返回一些JSON数据

然后，我有我的GWT客户端： http://localhost:4242/gwtclient 该客户端应该对REST服务进行异步调用。

我是新手，所以我的第一个想法是做以下事情：

RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, URL.encode("http://localhost:4242/myrestservice/getobject"));
builder.setHeader("Accept", "application/json");
builder.setCallback(new MyObjectDescCallback());    
builder.setRequestData("");
Request req  = builder.send();

...

final class MyObjectDescCallback implements RequestCallback {
            public void onError(Request request, Throwable exception) {
                showAlert("error = "+exception.getMessage());

                GWT.log(exception.getMessage());
       }
            public void onResponseReceived(Request request, Response response) {
showAlert("response = " + response.getStatusCode());
//Do my stuff here
}
}
}

不幸的是，我没有回复。

我检查了Rest服务，它确实发送了对象

似乎我的GWT应用程序没有得到答案。

知道如何让它发挥作用吗？

更新

以下是我使用Firebug的结果：

Response Headers
Server  Apache-Coyote/1.1
Content-Type    application/json
Transfer-Encoding   chunked
Date    Sun, 24 Apr 2011 11:04:15 GMT

Request Headers
Host    127.0.0.1:4242
User-Agent  Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Accept  application/json
Accept-Language en-us,en;q=0.5
Accept-Encoding gzip, deflate
Accept-Charset  ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive  115
Connection  keep-alive
Referer http://localhost:4242/gwtclient/gwtclient.html
Origin  http://localhost:4242

但是我得到了response.getStatusCode（）= 0 空洞的回应！

更新2：

我现在感觉很蠢......

问题实际上是SOP ......

我使用的是URL localhost，但在我的代码中我使用的是127.0.0.1！

...该死

Answer 1

您说您想要使用Async回调，但您从不在代码中使用new AsyncCallback<string>()。这就是我用gwt应用程序对服务器进行异步调用的方式:(我不使用JSON，但我认为这并不重要）

request object = new request();
object.getMessageXml("test.php", "GET", null, new AsyncCallback<String>() {

    @Override
    public void onFailure(Throwable caught) {
        //error handling
    }

    @Override
    public void onSuccess(String result) {
        // do some stuff with the result
    }
});

这是请求类：

public void getMessageXml(String file, String type, String requestData, final AsyncCallback<String> callback) {

        RootLayoutPanel.get().addStyleName("loading");

        final String url = "test/" + file;
        RequestBuilder rb;

        try {
            if(type == "POST") {
                rb = new RequestBuilder(RequestBuilder.POST, URL.encode(url));
            }
            else {
                rb = new RequestBuilder(RequestBuilder.GET, URL.encode(url));
            }

            rb.setHeader("Content-Type", "application/x-javascript; charset:ISO-8859-1");
            rb.sendRequest(requestData, new RequestCallback() {

                @Override
                public void onResponseReceived(Request request, Response response) {

                    if(Response.SC_OK == response.getStatusCode()) {

                        callback.onSuccess(response.getText()); 
                    }
                    else {
                        //error 
                    }
                    RootLayoutPanel.get().removeStyleName("loading");   
                }

                @Override
                public void onError(Request request, Throwable exception) { 
                    callback.onFailure(exception);
                }   
            }); 
        }
        catch(RequestException rex) {
            callback.onFailure(rex);
        }   
    }

[编辑：] 也许你找到了here:

GWT - 来自REST服务的CallBack没有答案

1 个答案: